1 /*
   2  * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 #include <sys/types.h>
  27 #include <sys/socket.h>
  28 
  29 #ifdef __solaris__
  30 #include <unistd.h>
  31 #include <stropts.h>
  32 
  33 #ifndef BSD_COMP
  34 #define BSD_COMP
  35 #endif
  36 
  37 #endif
  38 
  39 #include <sys/ioctl.h>
  40 
  41 #include "jvm.h"
  42 #include "jni_util.h"
  43 #include "net_util.h"
  44 
  45 #include "java_net_AbstractPlainDatagramSocketImpl.h"
  46 
  47 static jfieldID IO_fd_fdID;
  48 
  49 static jfieldID apdsi_fdID;
  50 
  51 
  52 /*
  53  * Class:     java_net_AbstractPlainDatagramSocketImpl
  54  * Method:    init
  55  * Signature: ()V
  56  */
  57 JNIEXPORT void JNICALL
  58 Java_java_net_AbstractPlainDatagramSocketImpl_init(JNIEnv *env, jclass cls) {
  59 
  60     apdsi_fdID = (*env)->GetFieldID(env, cls, "fd",
  61                                    "Ljava/io/FileDescriptor;");
  62     CHECK_NULL(apdsi_fdID);
  63 
  64     IO_fd_fdID = NET_GetFileDescriptorID(env);
  65 }
  66 
  67 /*
  68  * Class:     java_net_AbstractPlainDatagramSocketImpl
  69  * Method:    dataAvailable
  70  * Signature: ()I
  71  */
  72 JNIEXPORT jint JNICALL Java_java_net_AbstractPlainDatagramSocketImpl_dataAvailable
  73 (JNIEnv *env, jobject this) {
  74     int fd, retval;
  75 
  76     jobject fdObj = (*env)->GetObjectField(env, this, apdsi_fdID);
  77 
  78     if (IS_NULL(fdObj)) {
  79         JNU_ThrowByName(env, JNU_JAVANETPKG "SocketException",
  80                         "Socket closed");
  81         return -1;
  82     }
  83     fd = (*env)->GetIntField(env, fdObj, IO_fd_fdID);
  84 
  85     if (ioctl(fd, FIONREAD, &retval) < 0) {
  86         return -1;
  87     }
  88     return retval;
  89 }